This CL updates the internals to use AddressSpace instead of the old
StorageClass name.
Bug: tint:1404
Change-Id: Iecc208e839453437f4d630f65e0152206a52db7e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/104420
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Auto-Submit: Dan Sinclair <dsinclair@chromium.org>